Penal colony

Penal colonies were remote prison facilities with characteristics that varied in accordance with the needs and philosophies of their governing cultures. Typically, a sentence to a penal colony differed from normal incarceration by charging the inmate to perform a service or labor, or to help facilitate their own rehabilitation.

The stipulations for the inmates of the prison included the simple fact that no one could escape from below. If prisoners worked well, they would be treated well; if they worked badly, they would be exiled to the asteroid's frozen surface, where nothing could survive for very long.

The AngosianLunar V colony was created for its genetically-enhanced soldiers who previously participated in the Tarsian War. According to the Angosian government, the soldiers were placed there "for their own protection as well as that of others." Despite the fact that they made every effort to make the colony as amiable for its "colonists" as possible, the fact remained that it was still a prison. (TNG: "The Hunted")